LAKE BUENA VISTA, Fla. — The Nationals lost Adrian Nieto in Thursday’s Rule 5 draft to the White Sox, who are hoping the 24-year-old catcher has progressed enough to spend 2014 in the major leagues.

Nieto, a fifth-round pick in the 2008 draft, was well-liked by Nationals officials, but his slow development (he hasn’t advanced beyond Class A in six professional seasons) coupled with his standing on the organizational depth chart behind fellow catchers Jhonatan Solano and Sandy Leon left him unprotected for the Rule 5 draft.

“For us, I think it speaks to the depth of the system,” vice president of player development Doug Harris said. “Those are tough decisions when you get to that next guy, or next couple of guys. We do value his skill-set. Obviously being a catcher in A-ball, we have to prioritize our guys, so we made that decision.”

Nieto’s professional career got off to a rocky start; he hit .210 over his first three minor-league seasons and then was suspended 50 games in 2011 after testing positive for a pair of performance enhancing drugs. But he rebounded after a demotion to short-season Class A Auburn and this season hit .285 with a .373 on-base percentage in 110 games at high-Class A Potomac.

Nieto then hit .271 in 13 games in the Arizona Fall League, impressing scouts with his performance against higher-level prospects and making him a candidate to be lost in the Rule 5 draft.

“He’s done a terrific job,” Harris said. “Our staff deserves a lot of credit. Adrian struggled for several years with us, and we actually took a step back with him and kind of restarted his career going back to Auburn. It jump-started him. He matured a great deal, and we’re very proud of what he accomplished.”

Per the draft’s rules, the White Sox will pay the Nationals $50,000 to acquire Nieto. He must remain on their major-league roster for the entire 2014 season or else be offered back to Washington for $25,000.

The Nationals, who entered Thursday with a full 40-man roster, were ineligible to select any players in the major-league portion of the Rule 5 draft, but they did acquire two players in the Class AAA portion:

— Theo Bowe, a 23-year-old outfielder from the Reds organization who stole 70 bases in 2012 but struggled to a .206 batting average and .260 on-base percentage this season at Class AA. Harris said Bowe is seen as something of a replacement for Billy Burns, who was traded to the Athletics on Wednesday for left-hander Jerry Blevins.

— Martires Arias, a 23-year-old right-hander from the Mets organization who has raw skills but has yet to pitch above the rookie Appalachian League.